Info derived from imdb. Only movies/shows 2012-on noted by name. Only actor who made 9+ appearances on the show noted (which does for better or worse eliminate the Hello Larry cast).
Conrad Bain (Philip Drummond): died in 2013.
Gary Coleman (Arnold Jackson): died in 2010.
Todd Bridges (Willis Jackson): in College Fright Night (2014), Tesla Effect (2014 video game), Monsters on Main Street (2014), Hotel P (1 episode c2014), Precious Mettle (2014), Turning Point (2012), Dead Ringer (2015), Bar Chronicles (2015), The White Sistas (2015), Dependent's Day (2015) in post-production; Roommates (3 episodes nd) in pre-production; as Self: The Jack and Triumph Show (1 episode 2015), The Insider (1 episode 2014), Exhale (1 episode 2013), Oprah: Where Are They Now? (1 episode 2013), Access Hollywood Live (1 episode 2013), Marie (1 episode 2013), TSI: Hollywood (2013), The Smoking Gun Presents: World's Dumbest (14 episodes 2012-2013), Hollywood Uncensored with Sam Rubin (1 episode 2012), That's My Boy (2012).
Dana Plato (Kimberly Drummond): died in 1999.
Mary Jo Catlett (Pearl Gallagher): in The SpongeBob Movie: Sponge Out of Water (2015), Lucky Stiff (2014), Let's Be Cops (2014), Instant Mom (1 episode 2014), SpongeBob SquarePants (10 episodes 2012-2013), Rizzoli & Isles (1 episode 2013), Modern Family (1 episode 2013), Mr. Box Office (1 episode 2013), The Mentalist (1 episode 2013), Desperate Housewives (1 episode 2012), Shake it Up (1 episode 2012), Did You Look for Work This Week? (2012); When the Moon Was Twice as Big (2016) in post-production; as Self: Teens Wanna Know (1 episode 2013), Carol Channing: Larger Than Life (2012); as Self, filming: Broadway: Beyond the Golden Age (2016).
Danny Cooksey (Sam McKinney): in Regular Show (2 episodes 2014-2015), Kung Fu Panda: Legends of Awesomeness (2 episodes 2012-2014), Pound Puppies (4 episodes 2012-2013), Kick Buttowski: Suburban Daredevil (23 episodes 2012), The Lorax (2012); DaZe: Vol. Too (sic) - NonSeNse (2015) in post-production
Shavar Ross (Dudley Ramsey): last known acting role in 2008; as Self: Crystal Lake Memories: The Complete History of Friday the 13th (2013).
Charlotte Rae (Edna Garrett): in Girl Meets World (1 episode 2014), Love Sick Love (2012); Ricki and the Flash (2015) in post-production; as Self: She's The Best Thing In It (2015), Good Morning America (1 episode 2014), Teens Wanna Know (1 episode 2013), The 2012 Annual Actors Fund Gala Awards (2012); as Self, filming: Broadway: Beyond the Golden Age (2016).
Dixie Carter (Maggie McKinney - 1): died in 2010.
Steven Mond (Robbie Jason): no known subsequent acting roles.
Nedra Volz (Adelaide Brubaker): died in 2003.
Nikki Swasey Seaton (Lisa Hayes): last known acting role in 1992; as Second Assistant Director: So Random! (4 episodes 2012).
Mary Ann Mobley (Maggie McKinney Drummond - 2): died in 2014; as Self: Cupcake Wars (1 episode 2012).
Janet Jackson (Charlene DuPrey): last known acting role in 2010; as Self: R&B Divas of All Time (2013), The 40th Anniversary American Music Awards (2012), The Savoy King: Chick Webb & the Music That Changed America (2012), The Tonight Show with Jay Leno (1 episode 2012).
Jason Hervey (Charlie): last known acting role in 2004; as Executive Producer: See Dad Run (45 episodes 2012-2014), I (Heart) Nick Carter (unknown episodes 2014), Hardcore Pawn: Chicago (17 episodes 2013), The Devil's Ride (6 episodes 2012), The Catalina (unknown episodes 2012); as Producer: Gretta Style (2012); as Self: The Playboy Morning Show (2 episodes 2012-2015), Good Morning America (1 episode 2014), Katie (1 episode 2014).